1. Department of Surgery, College of Medicine, Chungbuk National University, Cheoungju, Korea.
2. Department of Surgery, University of Ulsan College of Medicine, Seoul, Korea.
3. Department of Surgery, Sungkyunkwan University School of Medicine, Seoul, Korea.
4. Department of Surgery, Ewha Womans University School of Medicine, Seoul, Korea.
5. Department of Surgery, College of Medicine, Korea University, Seoul, Korea.
6. Department of Surgery, College of Medicine, Yonsei University, Seoul, Korea.
7. Department of Surgery, Konkuk University School of Medicine, Seoul, Korea.
8. Department of Surgery, Chonnam National University Medical School, Gwangju, Korea.
9. Department of Surgery, College of Medicine, The Catholic University of Korea, Seoul, Korea.
10. Department of Surgery, Chonbuk National University Medical School, Jeonju, Korea.
11. Department of Surgery, Seoul National University College of Medicine, Seoul, Korea.
12. Department of Surgery, National Health Insurance Service Ilsan Hospital, Goyang, Korea.
13. Department of Surgery, School of Medicine, Kyungpook National University, Daegu, Korea.
14. Department of Surgery, Hallym University College of Medicine, Chuncheon, Korea.
15. Department of Surgery, Yeungnam University college of Medicine, Daegu, Korea.